Piston
| Piston | |
|---|---|
| |
| Category: | Functional |
| Function: | Extends in one axis to push or pull blocks |
| Fits small grid | |
| Mass: | 176.2 kg |
| Power: | 0.0002 MW |
| PCU: | 100 |
| Size: | 1x3x1 |
| Time to Build: | 12 sec |
| Fits large grid | |
| Mass: | 576.4 kg |
| Power: | 0.002 MW |
| PCU: | 100 |
| Size: | 1x3x1 |
| Time to Build: | 20 sec |
| Data Controls: | [edit] [purge] (?) |
The 
Piston is a Mechanical Block that can extend to a multiple of its length in one direction and pull attached blocks with it, thereby adding a push/pull mechanism to the game.
Usage
Pistons are used when building retractable landing feet, collapsible solar arrays, hidden turrets, extendable cranes and drill rigs, forklifts, large sliding doors, Mecha legs, lifting jacks for flipped vehicles, and much more.
The piston will convey power to the subgrids and can extend the conveyor system (see below). Pistons can actively push and pull. In contrast to hinges and rotors, you cannot set the braking torque of pistons to zero, which means that pistons cannot be moved passively like suspensions.
Examples:
- Drill Rigs: Drills on pistons can reach farther and dig wider and deeper mines.
- Connectors: The piston's conveyor ports are useful when building retractable base Connectors: They extend to connect and (un)load landed ships, and then disconnect and move out of the way before take-off, either manually or using Timer Blocks.
- Cranes: Crane joints supported by cross-bracing pistons are much more stable and can lift heavier grids than cranes built out of hinges or rotors alone.
Blocks connected by pistons will appear in different colors in the Control Panel Screen. The piston-attached grid is referred to as subgrid and is treated differently as far as steering is concerned.
Controls
Pistons can be grouped to share some controls.
To control pistons, use the control panel or assign the actions to toolbar slots:
- First set the piston's minimum and maximum extend distance.
- For large pistons, it ranges from 0 to 10m (total length 5m-15m)
- For small pistons, it ranges from 0 to 2m (total length 1-3m).
- Then set the speed of extending and retraction with the Velocity slider, maxing out at 5m/s in either direction.
- Click the Reverse button to extend and retract the piston.
Available Tool Bar Actions
- Block on/off
- Reverse - Switch movement direction between extend or retract
- Reset Velocity - Sets Velocity of all blocks to 0 = stop
- Increase Velocity - Gradually increase speed by 0.5 m/s
- Decrease Velocity - Gradually decrease speed by 0.5 m/s
- Increase Maximum Distance - Adjustable distance, extend longer, 0.1 m increments
- Decrease Maximum Distance - Adjustable distance, extend shorter, 0.1 m decrements
- Increase Minimum Distance - Adjustable distance, retract less, 0.1 m increments
- Decrease Minimum Distance - Adjustable distance, retract more, 0.1 m decrements
- Add Piston Head - Restores the subgrid attachment part if the head was destroyed.
How to stabilise grids
Don’t connect two pistons to the same grids on both ends and then set the pistons to different speeds or different extensions, because that would cause an impossible situation and stress to which the simulation likely reacts with a rapid unscheduled disassembly.
When connected one to another to form subgrids, pistons can bend or push subgrids into one another, and generate a lot of vibration and shake the grid apart (also known as Clang). In general, it's safest to use mechanical blocks on static grids.
On the Control Panel Screen (Experimental mode), enable the Share Inertia Tensor setting of the subgrid pistons. Do not enable Share Inertia Tensor on the first piston that’s attached to the main grid. This equalises the virtual masses to achieve more stable behaviour.
If you have to use mechanical blocks while flying/driving a mobile grid, it's recommended to set a 
Gyroscope on override with 0 RPM on all axes for stabilisation. Optimally, park, and lock the grid safely to the ground with 
Landing Gear while using mechanical blocks. This will help greatly to reduce shaking.
Construction
Pistons exist for large and small grid. They are made up of two parts, the base and the head. After you place a piston base, the head is added automatically. You must weld up both parts for the piston to be functional.
They can attach to blocks on the base end and head end, but not on the cylindrical sides. The narrow sides of the piston head can also attach to blocks.
Pistons have inventory doors on their head and base, allowing items to be transferred through them using the conveyor system. The small grid pistons interface with Small Conveyors only, due to their hatch size, and are bound by the same item size restrictions as small conveyors are.
Tip: If you notice a disruption in your conveyor system, but all conveyor tubes indicate a green light, remember to also check the integrity of your pistons – especially check the piston heads for damage!
Dimensions
Offset Added By Each Piston
You might notice that even when a piston is fully retracted or extended, blocks placed on the piston head will be slightly offset from the original grid, in the direction the piston is facing. This can cause to a slight step when boarding and disembarking piston elevators, and could cause issues when using pistons along with other mechanical blocks for advanced geometric constructions. The exact offsets from the grid as as follows:[1]
| Block type | Offset (meters) |
|---|---|
| Large grid piston | 0.158463 |
| Small grid piston | 0.031542 |
Total Lengths of Pistons
| Size | Position | Length (blocks) | Length (meters) |
|---|---|---|---|
| Large Grid | Fully Retracted | 2.0633852 | 5.158463 |
| Fully Extended | 6.0633852 | 15.158463 | |
| Small Grid | Fully Retracted | 2.063084 | 1.031542 |
| Fully Extended | 6.063084 | 3.031542 |
Recipe
| Piston | ||||
|---|---|---|---|---|
| Component | Large Ship/Station Required | Large Ship/Station Optional | Small Ship Required | Small Ship Optional |
 Computer | 2 | — | 1 | — |
 Motor | 4 | — | 2 | — |
 Large Steel Tube | 4 | — | 4 | — |
 Construction Comp. | 10 | — | 4 | — |
 Steel Plate | 10 | 5 | 2 | 2 |
Gallery
A crane built out of pistons, hinges, and rotors
Pistons expand and can be chained
References
